Publication

Advanced Multifunctional Nanocomposite Lab

Selected Representative Publications

  • 2023
  • Giant thermal rectification efficiency by geometrically enhanced asymmetric non-linear radiation
  • Seongkyun Kim , Taeyeop Kim , Jaehyun Sung , Yongjun Kim , Dongwoo Lee and Seunghyun Baik Materials Horizons
  • Thermal rectification is an asymmetric heat transport phenomenon where thermal conductance changes depending on the temperature gradient direction. The experimentally reported efficiency of thermal rectification materials and devices, which are applicable for a wide range of temperatures, is relatively low. Here we report a giant thermal rectification efficiency of 218% by maximizing asymmetry in …
  • 2022
  • Invariable resistance of conductive nanocomposite over 30% strain
  • C. MUHAMMED AJMAL, SEOKJAE CHA, WONJOON KIM, K. P. FASEELA, HEEJUN YANG, AND SEUNGHYUN BAIK Science Advances
  • The dependence of the electrical resistance on materials’ geometry determines the performance of conductive nanocomposites. Here, we report the invariable resistance of a conductive nanocomposite over 30% strain. This is enabled by the in situ–generated hierarchically structured silver nanosatellite particles, realizing a short interparticle distance (4.37 nm) in a stretchable silicone rubber matr…
Non-oxidized bare copper nanoparticles with surface excess electrons in air
Author
Kyungwha Chung, Joonho Bang, Athira Thacharon, Hyun Yong Song, Se Hwang Kang, Woo-Sung Jang, Neha Dhull, Dinesh Thapa, C. Muhammed Ajmal, Bumsub Song, Sung-Gyu Lee, Zhen Wang, Albina Jetybayeva, Seungbum Hong, Kyu Hyoung Lee, Eun Jin Cho, Seunghyun Baik,
Journal
Nature Nanotechnology
Vol
17
Page
285-291
Year
2022
Copper (Cu) nanoparticles (NPs) have received extensive interest owing to their advantageous properties compared with their bulk counterparts. Although the natural oxidation of Cu NPs can be alleviated by passivating the surfaces with additional moieties, obtaining non-oxidized bare Cu NPs in air remains challenging. Here we report that bare Cu NPs with surface excess electrons retain their non-oxidized state over several months in ambient air. Cu NPs grown on an electride support with excellent electron transfer ability are encapsulated by the surface-accumulated excess electrons, exhibiting an ultralow work function of ~3.2 eV. Atomic-scale structural and chemical analyses confirm the absence of Cu oxide moiety at the outermost surface of air-exposed bare Cu NPs. Theoretical energetics clarify that the surface-accumulated excess electrons suppress the oxygen adsorption and consequently prohibit the infiltration of oxygen into the Cu lattice, provoking the endothermic reaction for oxidation process. Our results will further stimulate the practical use of metal NPs in versatile applications.